tbuckley/cabot-search huggingface dataset:
EXTH-88. DOCETAXEL TARGETS AGGRESSIVE METHYLATION PROFILES AND SERVES AS A RADIOSENSITIZER IN HIGH-RISK MENINGIOMAS
Authors: Mark Youngblood, Anh Tran, Wenxia Wang, Shejuan An, Denise Scholtens, Lyndsee Zhang, Kaitlyn O’Shea, Jenny Pokorny, Stephen Magill, Sean Sachdev, Rimas Lukas, Atique Ahmed, Dusten Unruh, Jordain Walshon, Kathleen McCortney, Yufen Wang, Aneta Baran, Felix Sahm, Kenneth Aldape, James Chandler, Amy Heimberger, David James, Craig Horbinski
Journal: Neuro-Oncology (2022)

Abstract DNA methylation profiling has emerged as a transformative prognostic tool in meningiomas, identifying distinct epigenetic subgroups that share unique clinical and biological features. Hypothesizing that methylation patterns may also reflect underlying pathogenic mechanisms, we investigated if this modality could be informative for the selection of efficacious chemotherapies in meningiomas, focusing on FDA-approved compounds that are well-tolerated in patients. Using a methylation dataset of 210 tumors, we identified 981 genes in which adjacent CpG sites were predictive of progression-free survival. Pathway enrichment of these genes nominated Docetaxel as a candidate therapeutic; a well-established taxane that is routinely used for breast, prostate, and lung cancers. Using 15 primary patient-derived cultures and 2 cell lines, we found that Docetaxel could inhibit meningioma growth at concentrations that were favorable relative to other cancers. This drug triggered apoptosis in meningiomas of all tumor grades and methylation classes, with IC50 values ranging from 0.8nm to 4.4nm in vitro. Combining Docetaxel with radiation therapy resulted in synergistic cytotoxic effects on meningioma cultures, associated with elevated markers of cell death and dsDNA breaks. We confirmed our results via orthotopic meningioma mouse models of the cell lines CH157 and IOMM-Lee, which exhibited dose-dependent improvements in mortality and tumor volume in response to Docetaxel and radiation. Our results leverage DNA methylation patterns to repurpose FDA-approved medications in the treatment of meningiomas, and suggest a clinical trial of Docetaxel with radiotherapy may be efficacious in higher-grade lesions.
DNAR-11. CHARACTERIZING THE GENOMIC CONSEQUENCES OF G-QUADRUPLEX STABILIZATION IN ATRX-DEFICIENT HIGH-GRADE GLIOMA
Authors: Sharvari Dharmaiah, Brandon Chen, Prit Benny Malgulwar, Vasudev Tadimeti, Ahsan Farooqi, Jason Huse
Journal: Neuro-Oncology (2022)

Abstract α-thalassaemia/mental retardation X-linked (ATRX) mutations are a critical molecular marker for high-grade glioma (HGG). These mutations lead to accumulations of abnormal DNA secondary G-quadruplex (G4) structures, thereby inducing replication stress and DNA damage. As G4s arise at GC-rich regions (i.e., pericentromeric and telomeric regions), ATRX-deficiency alters genome-wide accessibility of chromatin and causes transcriptional dysregulation. However, the genomic consequences of this in the context of ATRX-deficiency are poorly understood. Our goal is to target ATRX deficiency through G4 stabilizers, a class of novel small molecule compounds that selectively bind to and stabilize G4s. Using a combination of functional experiments such as cell viability, western blot, flow cytometry, RNA-sequencing (RNA-seq), and immunofluorescence (IF), we evaluated the mechanisms that drive selective lethality upon G4 stabilization. Patient-derived glioma stem cells (GSCs) were treated with either vehicle (DMSO) or varying doses of CX-5461 (G4 stabilizer, Senhwa Biosciences). Excitingly, ATRX-deficient GSCs demonstrate dose-dependent enhanced sensitivity to G4 stabilization, compared to ATRX-intact and vehicle controls. Cell viability assays confirmed the specificity of CX-5461 in comparison to other commercially used G4 stabilizers. G4 stabilization activated p53-independent apoptosis and exhibited G2/M arrest in ATRX-deficient GSCs and, interestingly, upregulated expression of both ATR and ATM pathways, indicating enhanced replication stress and DNA damage, respectively. IF staining confirmed enhanced induction of replication stress and DNA damage markers 53BP1 and gH2AX. Our preliminary findings suggest that ATR and ATM activation leads to Cyclin D1 degradation and inhibition of transcription factor NF-κB, thereby driving apoptosis. In fact, RNA-seq analyses revealed positive enrichment of apoptosis, DNA repair, and NF-κB pathways and negative enrichment of the G2/M checkpoint in ATRX-deficient GSCs treated with CX-5461. Our work defines mechanisms of action and efficacy of a novel therapeutic strategy for pre-clinical ATRX-deficient HGG models, with strong implications for other ATRX-deficient cancers and potential translation into clinical practice.
TMIC-69. MITOCHONDRIAL TRANSFER FROM ASTROCYTES ENHANCES METABOLISM AND DRIVES PROLIFERATION OF GLIOBLASTOMA
Authors: Dionysios Watson, Defne Bayik, Adam Lauko, Samuel Sprowls, Gauravi Deshpande, Sarah Wilifford, Katie Troike, Daniel Silver, Sabrina Wang, Juliana Seder, Kristen Kay, Anita Hjelmeland, Justin Lathia
Journal: Neuro-Oncology (2022)

Abstract Mitochondrial transfer occurs both in stroke (central nervous system) and inflammatory pain (peripheral nerves). However, its role in glioblastoma (GBM) remains poorly understood. We hypothesized that mitochondrial transfer from non-malignant to GBM cells supports tumor metabolism and growth. Using transgenic mice expressing fluorophore-tagged mitochondria, we found that ~50% of orthotopically-implanted mouse GBM cells acquire mitochondria. Brain-resident cells, especially astrocytes, were the primary mitochondrial donors in vitro and in vivo. Mitochondrial transfer also occurred from immortalized human astrocytes to patient-derived xenograft (PDX) models in vitro at rates of 15-35%. GBM cells that acquired mitochondria expressed higher levels of the ATP-synthase subunit ATP5A and produced more ATP, while metabolomics revealed multiple upregulated pathways in recipient cells. These data point to increased metabolic activity in recipient cells. In vivo, mouse GBM cells that acquired mitochondria were more likely to be in S/G2/M cell cycle phases. We observed a similar effect in PDX that acquired astrocyte mitochondria in vitro, suggesting that transfer drives GBM proliferation. Using sorted mouse and human GBM cells with/without in vitro astrocyte mitochondrial acquisition, we found that mitochondrial transfer promoted in vitro self-renewal and in vivo tumorigenicity, leading to significant reduction in survival and increased penetrance in orthotopic GBM models. Transfer in mouse and human systems was contact-dependent and was abrogated by physical separation of donor and recipient cells by transwell inserts. Pharmacologic inhibition of cytoskeleton and gap junctions did not affect transfer rate, while blocking growth-associated protein 43 (GAP43) function by c-Jun N-terminus kinase inhibition decreased transfer rate by 15-30%, suggesting a potential role of GAP43. Taken together, mitochondrial transfer comprises a fundamental, protumorigenic mechanism of GBM, enhancing metabolic activity and driving tumor cell proliferation. Elucidating the molecular machinery regulating astrocyte mitochondrial transfer and its downstream protumorigenic effects will lead to therapeutic opportunities targeting this understudied tumor microenvironment interaction.
EXTH-75. INTEGRATED STRESS RESPONSE ACTIVATORS SYNERGISTICALLY INDUCE APOPTOSIS AND SUPPRESS PROLIFERATION IN DIFFUSE INTRINSIC PONTINE GLIOMA
Authors: Orlandi Novak, Antje Arnold, Charles Eberhart, Eric Raabe
Journal: Neuro-Oncology (2022)

Abstract DIPG has elevated baseline activation of the integrated stress response (ISR), an evolutionarily conserved system that enables cells to tolerate various forms of stress. Activation of the ISR is indicated by increased expression of activating transcription factor 4 (ATF4). Intermediate levels of ATF4 protect cells from stress, while persistent high levels result in cell death. The imipridone drug ONC201 increases mitochondrial stress and ATF4 expression by binding to and activating the mitochondrial protease ClpP. Sal003 inhibits dephosphorylation of ATF4 upstream regulator, eIF2α. The retinoic acid derivative fenretinide induces ATF4, increases reactive oxygen species, and has clinical activity in pediatric patients with neuroblastoma. Because DIPG has a high baseline level of ATF4, we hypothesized that the ISR activators Sal003, ONC201, and fenretinide would synergize to kill DIPG. After determining the IC50 of Sal003, fenretinide, and ONC201, we treated patient-derived DIPG cell lines with low micromolar doses. The combination of Sal003 and ONC201 significantly increased apoptosis as measured by CC3 immunofluorescence in comparison to DMSO and single treatment (p&amp;lt; 0.0001, ANOVA). Western blots for cleaved PARP expression detected induction of apoptosis in DIPG treated with both Sal003 and ONC201 over DMSO and monotherapy treated cells. The combination also increased ATF4 expression. Since Sal003 is not clinically available, we treated DIPG cells with ONC201 and fenretinide. Synergy testing in JHH-DIPG1 showed an overall ZIP synergy score of 14 with inhibitory concentrations of both drugs in the nanomolar range. CC3 immunofluorescence indicated elevated apoptosis in the combination vs. DMSO (p&amp;lt; 0.0001, ANOVA). Western blots showed increased cleaved PARP, ATF4, p-eIF2α, and CHOP expression in DIPG treated with ONC201 and fenretinide. We are currently testing the efficacy of this combination in brain organoids and orthotopic DIPG xenografts. Our results suggest the combination of ONC201 with fenretinide could potentially serve as a therapy for DIPG.
INNV-14. PROSPECTIVE SURGICAL STUDY ON THE FEASIBILITY OF SEMI-AUTOMATED TISSUE COLLECTION, STABILIZATION, PRESERVATION, AND SITE TRANSFER IN GLIOBLASTOMA - IMPROVING UNDERSTANDING OF IMMUNE LANDSCAPE OF TUMOR
Authors: Alireza Mohammadi, Matthew Grabowski, Dionysios Watson, Adam Lauko, Justin Lathia, Manmeet Ahluwalia
Journal: Neuro-Oncology (2022)

Abstract INTRODUCTION Despite advances in targeted therapy and immunotherapy of many cancers, glioblastoma outcome is still suboptimal in part due to heterogeneity of tumor. Standard surgical approach for glioblastoma is to remove the enhancing tumor and adjuvant treatment used to treat residual infiltrative tumor in non-enhancing surgical wall. We evaluated samples from both areas using advanced techniques of intraoperative resecting, collecting and biologically preserving viable fresh tissue for evaluation of immune landscape and special genomics of tumor. METHODS 20 patients with glioblastoma enrolled in the study. Before removal of tumor, 3 different samples from central core, enhancing rim and non-enhancing portion of tumor were obtained using navigation assisted NICO Myriad. Fresh tissue was collected separately by an intraopertive Automated Tissue Preservation System (ATPS) and promptly prepare in iced-cold container for laboratory evaluation of tumor tissue viability, bio-banking and flow-cytometric analysis. RESULTS Average age was 65 years-old and 11 patients were female (55%). No adverse event was observed and on average, sampling added 10 minutes to surgical time. Flow-cytometry showed that non-enhancing portion of glioblastoma compared to enhancing tumor has less immune cells and different abundance of multiple subsets including lower CD8:CD4 ratio and more abundant of CD4 memory T-cells. However there remain activated/exhausted T-cells and suppressive myeloid cells in the non-enhancing tumor. Tissue is sent for micro-RNA analysis and next-generation sequencing as well. CONCLUSION Taken together, navigation assisted sampling and semi-automated tissue collection, stabilization, and preservation using ATPS is a safe and feasible technique to obtain viable cells for evaluation of heterogeneity of glioblastoma, especially for non-enhancing portion of tumor. This information can be used developing next-generation therapy. Initial results of flow-cytometry showed overall decreased leukocyte infiltration, with underrepresentation of selected immune cell subsets in non-enhancing tumor compared to enhancing portion. Further studies regarding micro-RNA analysis and next-generation sequencing are underway.
SURG-03. SURGICAL MANAGEMENT OF BRAIN METASTASIS FROM OVARIAN CANCER: A SYSTEMATIC REVIEW AND CASE SERIES
Authors: Meredith Costello, Malek Bashti, Martin Merenzon, Alexis Morell, Nitesh Patel, Dominique Higgins, Michael Kader, Ashish Shah, Daniel Eichberg, Evan Luther, Ricardo Komotar, Michael Ivan
Journal: Neuro-Oncology (2022)

Abstract INTRODUCTION Ovarian cancer is a rare cause of brain metastasis requiring neurosurgical intervention. Management strategies vary and prognostic factors are not well known. OBJECTIVE We aim to systematically review the literature on management and outcomes of ovarian cancer brain metastasis and compare it with our experience. METHODS Systematic review was performed using PRISMA guidelines. Databases were sourced from inception to April 2022. Study selection was based on predetermined inclusion/exclusion criteria. A simultaneous retrospective analysis was performed on patients from our institution who underwent evaluation and treatment for metastatic intracranial lesions of ovarian origin. RESULTS Literature search generated 214 articles. Twelve were ultimately selected, representing 428 brain metastasis (BM) patients from ovarian cancer. Patients age from 27-80 years. The interval from cancer diagnosis to BM ranged from 0 – 226.2 months. Surgical resection (SR), stereotactic radiosurgery (SRS), and whole-brain radiotherapy were the most frequently used treatment modalities. Individual patients’ overall survival following BM diagnosis ranged from 0 – 173 months. For our institutional analysis, 9 patients were included with median age of 56 years. Median interval from diagnosis to BM was 51 months. Four patients were treated with SR and adjuvant SRS. Two patients had SR and SRS with additional extraventricular drain placement. Two patients had SR only, and one received only SRS. Median radiation dose received was 20 Gy. For those who experienced progression, median progression-free survival was 14 months. One patient exhibited no progression at the time of analysis. Three patients were alive at the time of analysis with two others lost to follow-up. CONCLUSION brain metastases following ovarian cancer are a rare outcome carrying a poor prognosis. Multimodal therapies, specifically SR and SRS, correlate with increased survival. Further study is needed to better guide optimal management, with particular attention to the benefits of resection with targeted adjuvant radiation.
TMIC-17. DISCOVERING DOMINANT TUMOR CHARACTERISTICS IN CYSTIC GLIOBLASTOMA
Authors: Zhihua Chen, Yifeng Miao, Shun Yao, Denis O’Meally, David Frankhouser, Biao Tang, MingHui Li, Paul Frankel, Mari Shahmanyan, Yongming Qiu, Russell C Rockne
Journal: Neuro-Oncology (2022)

Abstract BACKGROUND As a rare subtype of glioblastoma (GBM), the genetic features and outcomes in cystic GBM (cGBM) are largely unknown. This study aimed to evaluate the survival of cystic features, investigate genomic patterns and the immune microenvironment in patients with cGBM. METHODS Gd T1-weighted, T2-weighted, T2-Flair, DWI or ADC images were used to classify cGBM or noncystic GBM (non-cGBM). Clinical information from IvyGAP, EGA databases and Chinese cohort were used for survival analysis. Fresh cystic fluid and residual tumor tissue were collected to evaluate immunological components, pathological and genomic differences between cGBM and non-cGBM. Data from IvyGAP were included to determine difference of molecular feature among substructure. RESULTS 143 cases with cGBM and non-cGBM were screened to compare survival outcomes. Cystic features were to confer a survival benefit. It was an independent prognostic factor irrespective of IDH, MGMT and therapeutic regimen. cGBM patients have a hypomethylation state compared to non-cGBM. Active immune cells such as CD4+, CD8+ T cells were present in the cystic fluid and infiltrated into tumor. 10 cytokines/chemokines were only detected in cystic fluid, 8 cytokines/chemokines increased two-fold in cystic fluid than in peripheral blood serum (PBPs). Much differential methylated position (DMPs), differentially expressed genes (DEGs), Gene Set Enrichment Analysis (GSAE), Functional Epigenetic Modules (FEM) networks and molecular feature of substructural regions were different between cGBM and non-cGBM. CONCLUSION These results imply that cGBM could be a new subtype and has distinctive immune microenvironment which may have potential value correlating with prognosis.
EXTH-12. PRECLINICAL AND CASE STUDY EXAMINATION OF THE COMBINATION OF THE CLPP AGONIST ONC201 WITH THE PI3K/AKT INHIBITOR PAXALISIB FOR THE TREATMENT OF DIFFUSE MIDLINE GLIOMA
Authors: Evangeline Jackson, Ryan Duchatel, Mika Persson, Abdul Mannan, Sridevi Yadavilli, Sarah Parackal, Shaye Game, Wai Chin Chong, Samantha Jayasekara, Marion Le Grand, Padraic Kearney, Alicia Douglas, Izac Findlay, Dilana Staudt, Zacary Germon, David Skerrett-Byrne, Brett Nixon, Nathan Smith, Esther Hulleman, Bryan Day, Geoffrey McCowage, Frank Alvaro, Sebastian Waszak, Martin Larsen, Yolanda Colino-Sanguino, Fatima Valdes-Mora, Andria Rakotomalala, Samuel Meignan, Eddy Pasquier, Nicholas Vitanza, Javad Nazarian, Carl Koschmann, Jason Cain, Sabine Mueller, Matthew Dun
Journal: Neuro-Oncology (2022)

Abstract Diffuse midline gliomas (DMGs), including those of the pons (diffuse intrinsic pontine glioma - DIPG), are pediatric CNS tumors recognized as the most lethal of all children’s cancers. Palliative radiotherapy remains the only approved treatment, with survival just 9-11 months post-diagnosis. The brain-penetrant small molecule therapy, ONC201, shows preclinical and emerging efficacy in early-stage clinical trials. However, patients invariably develop resistance, with some patients and models completely refractory to treatment. Using a powerful combination of pharmacology, proteomics, genomics, epigenetics, in vitro and in vivo modeling, across ten international laboratories, we have uncovered mechanisms underpinning resistance to ONC201. We find ONC201 elicits antagonism of the Dopamine receptor D2 (DRD2), whilst also causing mitochondrial degradation through potent agonism of the mitochondrial protease CLPP. This drives proteolysis of the electron transport chain (ETC) proteins including Succinate dehydrogenase A (SDHA) and the critical mitochondrial tricarboxylic acid (TCA) cycle regulator, Isocitrate dehydrogenase 3B (IDH3B). Loss of TCA activity reduces α-ketoglutarate and inhibits lysine demethylation, increasing methylation of H3K4me3 and H3K27me3, thus, altering the epigenome of DIPG. Mitochondrial disruption elicited redox-activated RAS-PI3K/AKT signaling, counteracted using the PI3K/AKT inhibitor paxalisib. The combination of ONC201 and paxalisib synergistically extended survival of two aggressive DIPG PDX models (SU-DIPG-VI vehicle=73 vs. combination=100-days, p=0.0027; SF8626 vehicle=36 vs. combination=43-days, p=0.0002). Compassionate access to this combination (n=2 patients; immediately post-RT and following re-RT) resulted in dramatic reductions in tumor volume, extending overall survival for the patient at diagnosis and the patient at progression (e.g., MR axial diagnosis scan = 1554 mm2, following twelve months on the combination, current tumor volume = 464 mm2 (~70% reduction), patient remains in progression free survival, 15 months since diagnosis). The clinical utility of our preclinical data is currently under investigation in the PNOC022 clinical trial (NCT05009992).
CTIM-09. ENRICHED TCR/BCR VDJ REARRANGEMENTS CORRELATE WITH MRI AND SURVIVAL OUTCOMES IN PATIENTS WITH RECURRENT HIGH-GRADE GLIOMA TREATED WITH CAN-3110
Authors: E Antonio Chiocca, Hiroshi Nakashima, Xiaokui Mo, Isaac Solomon, Alexander Ling, Jared Woods, Joshua Bernstock, Genaro Villa, Raziye Piranlioglu, Ana Montalvo Landivar, Nafisa Masud, Daniel Triggs, James Grant, Patrick Y Wen, Eudocia Lee, Lakshmi Nayak, Ugonma Chukwueke, Tracy Batchelor, David Krisky, Estuardo Aguilar-Cordova, Laura K Aguilar, Soledad Fernandez, Christopher Matheny, Andrea Manzanera, Francesca Barone, Paul Peter Tak, Keith Ligon, David A Reardon
Journal: Neuro-Oncology (2022)

Abstract BACKGROUND CAN-3110 (rQNestin34.5v2) is an HSV-1 oncolytic viral immunotherapy with one copy of the inflammatory ICP34.5 gene under transcriptional control of the Nestin glioma-specific promoter. We completed a phase 1 sequential dose-escalation trial of CAN-3110 in recurrent high-grade glioma (rHGG). METHODS CAN-3110 was injected intratumorally starting at 1x106 plaque forming units (pfu) and dose- escalated by half log up to 1x1010 pfu in biopsy confirmed rHGG. An expansion cohort of 12 patients was then accrued at 1x109 pfus. Blood and post-injection rHGG were collected. RESULTS 41 rHGG patients were treated (42 separate interventions): median age 56 years (range 27-74); 21 females, 20 males; median baseline KPS 90 (range 70-100). CAN-3110 administration was well-tolerated with no dose limiting toxicities. Median overall survival (mOS) was 11.9 months. Histologic and molecular analyses showed significantly increased T cell infiltration in post treatment samples with elevated T cell and/or B cell receptor (TCR/BCR) transcripts which correlated with patient survival (HR 0.26 for patients with elevated TCR/BCR rearrangements as compared to patients with low). Volumetric analyses of MRI suggest a trend between reduction in the relative change in tumor growth, TCR/BCRs enrichment and survival in CAN-3110 treated patients. CLINICAL IMPLICATIONS Administration of CAN-3110 into rHGG was well tolerated. OS of CAN-3110 treated subjects compare favorably to historical controls. The association of increased TCR/BCR transcripts with survival suggests that CAN-3110 induces T cell responses against rHGG, supporting further clinical development of CAN-3110 viral immunotherapy.
EPID-18. IATROGENIC IMMUNODEFICIENCY ASSOCIATED LYMPHOPROLIFERATIVE DISORDERS OF THE CENTRAL NERVOUS SYSTEM: A TREATMENT PARADOX
Authors: Ramya Tadipatri, Chukwuyem Ekhator, Ram Narayan, Amir Azadi, Kevin Yuen, Jai Grewal, Ekokobe Fonkem
Journal: Neuro-Oncology (2022)

Abstract BACKGROUND Primary central nervous system lymphomas (PCNSLs) have historically had dismal survival rates until the advent of high-dose methotrexate (HD-MTX) based chemotherapy regimens. With increasing prevalence of autoimmune disease and development of new immunosuppressants, a genetically distinct entity known as iatrogenic immunodeficiency associated lymphoproliferative disorder (LPD) has emerged. Many of these cases arise following methotrexate use, challenging feasibility of standard HD-MTX regimens. The aim of this study was to further characterize this disorder and determine the optimal management strategy. METHODS We describe a case of a 76-year-old female with iatrogenic immunodeficiency associated PCNSL successfully treated with surgical resection followed by an antiviral and rituximab based regimen. We then performed a systematic literature review and identified 58 cases of non-transplant iatrogenic immunodeficiency associated LPD involving the CNS. We used a linear probability statistical model to determine correlations with outcome. RESULTS Natalizumab was associated with EBV negative tumors (p = 0.023), and EBV positive tumors were associated with improved outcomes (p = 0.016). Surgical resection was associated with improved outcomes (p = 0.032), although limited by potential confounding effect. Antiviral treatment (p = 0.095), rituximab (p = 0.111), and SCT (p = 0.198) showed a trend toward improved outcomes. The remaining treatments including methotrexate showed no improvement. CONCLUSION We propose that surgical resection, rituximab, and antiviral treatment may be considered as an alternative to standard HD-MTX based regimens when managing iatrogenic immunodeficiency associated LPD of the CNS. Further study through prospective cohort studies or randomized clinical trials is warranted.